U-shaped and V-shaped palleovalleys and paleodepressions are identified on multifrequency seismic data in near-surface section (NSS) within three study areas in Vostochno-Prinovozemelsky area. ...Valleys of the Late Cretaceous and Quaternary ages and of different genesis are found in the first area of study. The palleovalleys of the Late Cretaceous age are V-shaped and U-shaped by their characteristic morphological properties and are likely formed as a result of the rivers erosional activity. Genesis of the buried valleys filled with Quaternary glacial sediments is usually connected to glacial plucking of the Late Quaternary glaciation, and they are similar to U-shaped paleovalleys. The tunnel valleys of Quaternary age that most likely were formed as a result from impact of ice sheet located to the east of the Novaya Zemlya archipelago in the Late Quaternary age were observed in the second study area. In contrast to the first two sites, isometric depressions of Quaternary age and controversial genesis were observed in the third one. The direction of the identified paleovalleys in some cases coincides with the submarine valleys indicated on the USSR Northern Seas submarine valleys map (Lastochkin, 1977) and the Kara Sea geomorphological map (Miroshnikov et al., 2021).
Results of a new analysis of negative particle yields in Au + Au collisions obtained by the STAR Collaboration in the first phase of the RHIC Beam Energy Scan (BES) program in the framework of
...-scaling approach are presented. The spectra were measured over a wide range of collision energy
GeV and transverse momentum of produced particles for different centralities at
The concept of the
-scaling based on self-similarity, locality, and fractality of hadron interactions at a constituent level is verified. The constituent energy loss as a function of energy and centrality of collision and transverse momentum of inclusive particle was estimated.
We present new results of analysis of top-quark differential cross sections obtained by the CMS Collaboration in pp collisions in the framework of the z-scaling approach. The spectra are measured ...over a wide range of collision energy s = 7 , 8 , 13 T e V and transverse momentum pT = 30−500 GeV/c of top-quark using leptonic and jet decay modes. Flavor independence of the scaling function ψ(z) is verified in the new kinematic range. The results of analysis of the top-quark spectra obtained at the LHC are compared with similar spectra measured in p ¯ p collisions at the Tevatron energy s = 1.96 T e V . A tendency to saturation of ψ(z) for the process at low z and a power-law behavior of ψ(z) at high z is observed. The measurements of high-pT is observed. The measurements of highspectra of the top-quark production at highest LHC energy is of interest for verification of self-similarity of particle production, understanding flavor origin and search for new physics symmetries with top-quark probe.
LES simulations at
R
e
= 1 × 10
5
and wind tunnel experiments at
R
e
= 5 × 10
5
were conducted to investigate the beneficial effect of an active flow control (AFC) technique on the aerodynamic ...performance of a simplified truck geometry. The paper involves the investigation of a synthetic jet actuator characterized by periodic blowing and suction that defines a zero net mass flux flow control mechanism. The actuation aims to suppress the flow separation occurring at the A-pillar (front rounded corner) of a truck cabin. The work flow is defined as it follows. First, LES at low Reynolds number are conducted for different disposition of the actuation slots. The results show a beneficial effect when the actuation slots are positioned in streamwise direction compared to spanwise (vertical) direction. Second, based on the previous considerations, wind tunnel experiments are conducted to verify and support the numerical findings. Both numerical solutions and experimental data show the same trend and the superiority of the streamwise slots actuation when compared to traditional vertical slot actuation. In particular, this work shows the weakness of a vertical slot actuation, when its location is not optimized. A small change in its positioning greatly worsen the efficacy of the separation control in terms of drag reduction and separation bubble length. The slot location directly affects the length of the separated flow region which its reduction can vary between 40–70% based on the positioning. Conversely, a streamwise actuation, spanning a larger portion of the curvature of a rounded A-pillar, is not affected by this behaviour and contributes up to 80% of the recirculation bubble reduction measured in the unactuated case. The effect of the location change and the orientation of a zero net mass flux jet slot is therefore investigated and discussed in this work.
—New data on the seafloor topography in the waters adjacent to the White Sea Biological Station of Moscow State University (Kandalaksha Bay) obtained with a multibeam echosounder (MBE) have made it ...possible to study the seabed relief in detail and to clarify the structure of Quaternary sediments in this area, substantially increasing the detail of the continuous seismoacoustic profiling (CSP) data obtained earlier. In the western part of the studied water area de Geer moraines have been identified for the first time in a complex of glacial deposits. These were formed during the Late Pleistocene glacial retreat in an eastern direction toward the recent deepwater part of the White Sea. In the deepwater area, according to the MBE and CSP data, the genesis of studied sediments occurred due to intensive gravitational processes at the end of the Late Pleistocene–Holocene. These new data may be indicative of “dead” ice in the White Sea Depression.
The results of a study of nitrogen-containing active regions based on superlattices grown on GaAs substrates are presented. Active regions based on alternating InAs and GaAsN layers were fabricated ...by molecular-beam epitaxy using a nitrogen plasma source. Based on the XRD analysis, the thicknesses and average composition of superlattice layers are estimated. The study of dark-field images obtained by transmission electron microscopy showed the presence of interdiffusion of InAs into GaAsN. The results of a study of the photoluminescence and electroluminescence spectra at different pump levels are presented. Efficient electroluminescence is demonstrated near 1150 nm with a full width at half-maximum of about ~90 meV.
In this paper, the experimental testing on an advanced solid sorption chiller based on a heat exchanger coated with a compact layer of SWS-1L (CaCl
2 in mesoporous silica gel) is presented. The ...experimental results showed a specific power of 150–200
W/kg of adsorbent and a cycle time of 10–20
min. These values are sensibly better (i.e. one order of magnitude different) than those measured in the same unit working with a SWS-1L pelletised bed. The cooling COP ranged between 0.15 and 0.3, depending on the operating conditions.
A shallow well was drilled in the East Siberian Sea for the first time with the purpose of geological study of the suture zone of deep waters of the Arctic Ocean and marginal structures of the ...continental shelf. The works have been carried out at the initiative of the Federal Agency on Mineral Resources (Rosnedra) in August 2022. The well was drilled by the Russian Geological Research Institute (VSEGEI) and Rosgeologia with the assistance of Rosneft and was linked to the Rosneft’s long-term stratigraphic drilling program. Drilling was accompanied by continuous seismic-acoustic profiling and well thermometry. The maximum depth of the well was 472 m from the bottom of the sea floor; 147.5 m of core was taken to a depth of 268 m. Two sedimentary sequences were identified in the section: the Lower Jurassic–Lower Cretaceous gently deformed sequence and the Upper Neogene–Quaternary horizontally lying sequence. The sequences are separated by a thick unsampled interval with horizons of confined waters. The Jurassic–Lower Cretaceous sequence composes a northwestern-dipping monocline broken by faults and probably belongs to the complex filling the Zhokhov marginal trough of the Verkhoyansk–Chukotka orogen on the Eastern Arctic shelf.
The near-shore zone of the East Siberian Sea is one of the least studied marine areas of the Russian Arctic. One of the important unsolved problems is the existence of a glacier sheet in the area of ...the New Siberian Islands, and the related debatable issue of the age and genesis of underwater ridges (bars) around the archipelago. Based on comprehensive analysis of the geological and geophysical data obtained by the Karpinsky Russian Geological Research Institute, St. Petersburg, Russia (VSEGEI) in 2018 and 2020 and subsequent laboratory studies, two types of submarine ridges, principally different in morphology, sediment composition, age, and genesis, were distinguished. The ridges of the first type located on the outer periphery of the underwater valley of the pra-Kolyma River and around New Siberia Island are asymmetric. They have a relative height of 1–2 m to 4–6 m, an average width of 2–4 km (up to a few tens of km), and an average length of 25–30 km (up to 100 km). According to the sampling data, the ridges of this type are composed of very dense clayey silts without an admixture of coarse clastic material. The age of the deposits forming the ridges is Late Pleistocene (18–13 ka BP). The Middle–Upper Pleistocene formations are exposed in the inter-ridge hollows. The composition, morphology, and age of the ridge deposits suggest that their genesis is associated with denudation processes, but the mechanism of their formation is not obvious. The ridges of the second type include a system of coastal bars located at a distance of up to 30 km from the coast of New Siberia Island and are composed of fine-grained, well-sorted sands. The width of the ridges varies from 1 to 2 km; the height, from 4 to 8 m; and the length is 10–15 km. They are slightly asymmetric in shape, with a gentler slope from the side of the island. This system of ridges was formed as a result of accumulative processes in the Holocene. The ridges of terminal moraines were not established within the seabed segments studied. The obtained data do not support the hypothesis of the extension of the Late Pleistocene ice sheet to the shelf.
The work explores the three-dimensional structure of the near field of a quasi-two-dimensional turbulent jet. The jet stream forms at an outflow from the rectangular channel with aspect ratio B/h ...equal to 1:2.5 into the channel, formed by two plane-parallel plates. The experiments were carried out for a wide range of Re number from 2 000 to 20 000. The measurements were performed using Tomographic PIV method with high time resolution. It is shown that for the whole investigated range of Re number in the near-field of the quasi-two-dimensional jet, there are formed secondary flows, caused by the presence of longitudinal vortex structures in the flow.
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